Superconductive Coupling Effects in Selectively Grown Topological Insulator-Based Three-Terminal Junctions

ACS Nano, vol. 19, pp. 3878–3885

Abstract

High Resolution Image Download MS PowerPoint Slide The combination of an ordinary s-type superconductor with three-dimensional topological insulators creates a promising platform for fault-tolerant topological quantum computing circuits based on Majorana braiding. The backbone of the braiding mechanism are three-terminal Josephson junctions. It is crucial to understand the transport in these devices for further use in quantum computing applications. We present low-temperature measurements of topological insulator-based three-terminal Josephson junctions fabricated by a combination of selective-area growth of Bi 0.8 Sb 1.2 Te 3 and shadow mask evaporation of Nb. This approach allows for the in situ fabrication of Josephson junctions with an exceptional interface quality, important for the study of the proximity-effect. We map out the transport properties of the device as a function of bias currents and prove the coupling of the junctions by the observation of a multiterminal geometry-induced diode effect. We find good agreement of our findings with a resistively and capacitively shunted junction network model.

Authors 5

1. Gerrit Behner corresponding Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

2. Abdur Rehman Jalil Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

3. Hans Luth Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

4. Detlev Grützmacher Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany

5. Thomas Schäpers corresponding Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany

   Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany